Ph.D. Student Project: Operational modelling of the nitrogen balance of oil palm plantations to reduce uncertainty in Life Cycle Assessment. Case study in Sumatra, Indonesia

Starting in Sept. 2014

Background and objectives  

Palm oil represents today more than 30% of the global vegetable oil demand. It is very emblematic of the challenges faced by agriculture, which must provide food, feed and fuel, but also be a vector of development while preserving the environment. The key point in the search of how palm oil systems can better address these challenges is to properly assess their performances notably in terms of environmental impacts. This is one of the objectives of the ANR SPOP research project which partly funds this Ph.D. project. Main environmental impacts of oil palm plantations are related to deforestation and greenhouse gas and pollutant emissions due to the application of synthetic fertilisers. This Ph.D. project focuses on the latter with emphasis on the nitrogen balance. Indeed, the emissions of reactive N (Nr) compound are the main sources of environmental impacts at the plantation scale, while fertilization costs play an important role in the farm profitability. Methods exist to estimate these Nr-emissions and integrate them into impact categories within the frame of Life Cycle Assessment (LCA). However, these methods are neither well adapted to tropical conditions nor sensitive to the specificities of perennial cropping systems. As a consequence, LCA results based on these methods are therefore very uncertain and hardly useful for making recommendations on practices.

The objective of the Ph.D. project is to improve the accuracy of LCA on palm oil systems through the improvement of the modelling of field Nr-emissions. This modelling must be consistent (accounting for the whole N-balance along the whole perennial cycle), sensitive to local conditions and practices, and easily implementable. Hence, the main pursued track will be to develop an operational model, such as an agro-environmental indicator, and to analyse the propagation of its uncertainty along the LCA characterisation pathways.

Description of tasks

The Ph.D. project will include both theoretical and field works, structured as follows in chronological order but with some overlapping:

Task 1 : Literature review on recent works on N-emission modelling (Wiltshire et al., 2012 ; Meier et al., 2012) with a focus on the tropics and perennial crops : available field data, emission factors, crop models and indicators (notably the INDIGO and I-Palm indicators).

Task 2 : In-depth review of all N-related pathways in LCA and uncertainty analysis methods with a focus on the accounting of spatial and temporal variability.

Task 3 : Development of the N-balance operational model based on both data from the literature and own field experiments needed to complete and validate the model.

Task 4 : Coupling the operational model and LCA with a specific attention paid to the sensitivity of the model to agricultural practices and the uncertainty propagation up to LCA results. Some bases for a generic method to combine indicators and LCA may be proposed.

Task 5 : Case studies on several contrasted cases of oil palm plantations in Sumatra, Indonesia

Expected outputs

At least 3 scientific publications in peer-reviewed journals should be written and compiled for the Ph.D. thesis (one for each of the tasks 1, 3, 5). One accepted publication is mandatory to defend the Ph.D. thesis.

Candidate requirements

Applicants should possess a university degree at MSc level in Agricultural or Environmental Sciences with an interest in biophysical modelling and uncertainty analysis. Applicants should be motivated to combine biophysical modelling at ecosystem level and LCA assessment. Proficiency in English (both spoken and written) is required, as well as good communication skills (oral and in writing).

Conditions of employment

Start date: September 2014

Duration of contract: 3 years

Monthly gross salary: 1700€

Working places:

• Montpellier (France), Cirad (1.5/3 time period),
• Field work in Sumatra (Indonesia) (1/3 time period)
• Stays in Paris (France) and Cairns (Australia) (0.5/3 time period)

Academic supervision

Advisor: Prof. Benoît Gabrielle (AgroParisTech, Paris, France)

Co-advisor : Cécile Bessou, Ph.D. (Cirad UPR 34, Montpellier, France)

Co-tutorship : Paul Nelson, Ph.D. (James Cook University, Cairns, Australia)

Field scientific partner : PT-SMART Research Center directed by Jean-Pierre Caliman, Ph.D. (Indonesia).

The Ph.D. student will benefit from a strong research dynamics within Cirad ACV-research team, the ELSA platform and the LCA Agrifood Asia network.

Applications (closing on June 23. 2014)

Candidates should send a resume, motivation letter and references in English (with acknowledgment) to :

Cécile BESSOU. 
 E-mail : cecile.bessou@cirad.fr

Phone: +33 4 67 61 44 87

Cirad UR34 Performance of perennial cropping systems
 F-34398 Montpellier CEDEX 5

Cc : Benoît GABRIELLE

E-mail: Benoit.Gabrielle@agroparistech.fr  

Phone: +33 1 30 81 55 51

UMR INRA AgroParisTech Environnement et grandes cultures

78850 Thiverval-Grignon, France

Additional information may be obtained from Cécile BESSOU